Tamperproof plug valve



Feb. 19, 1952 J. G. BRADBURY 2,586,453

TAMPER-PROOF PLUG VALVE Fi led Jan. 29, 1948 F/G. J F/G. 3

INVENTOR. nea (5t 5700 6214!" BY j Patented Feb. 19, 1952 UNITED PATENT QFFICE.

I MPERPROOF PLUG James G. Bradbury, Erie, Pa, assignorte Hays Manufacturing Company, Erie, Pa.

Application January 29, 1am. sesame sun 2 Claims.

This invention relates generally to plug valves and more particularly to tamper proof means in; a plug valve to prevent unauthorized disconnection thereof. 1

Caps or covers have been utilized to coverthe nuton the depending threaded portion of the stop plug in plug valves but it has been found that these caps are easily removed by unauthorized persons and the nut is turned. Many-utility companies in the country have been and are being sued because stop plugs have been blown out after the shearing off of the lower end of the stop plug wherein gas passed from the gas line and firesfeigplosions and other damage resulted. The shearing of the lower end of the plug is usually caused when the plug freezes and in an attempt to free it the nut is' rotated in the wrong direction or it is corroded. The threads are stripped in many cases. Furthermore, these prior plugs tend to freeze wherein rotation almost impossible.

It accordingly, an object of my invention to overcome the above and other defects inpresent plug valves and it is more particularly an object of my. invention. to. provide a plug valve which is tamper-proof, which is economical in cost, economical in construction, economical in manufacture, and efiicient in operation.

Another; ohjeot of mention to provide spring means in conjunction with a tapered plug in a. plug val which usesthe plug to seat. on its. seat at, all times and which minimizes, the ireez n of. th p u on s seat.

Another ob ect f y vention s o. pro ide novel threaded means for connection to. the hreaded depe i n. or a. p in a p u valve which cannot be engaged by any type of wrench.

Another object of my. invention is to provide aplug valve wherein the threaded member connecting the plug cannot be rotated to cause accidents and explosions.

Another object of my invention is to provide a plug valve which cannot be disassembled except by the use of a drill.

Another object of my invention is to provide a spring urged plug which may be freed by tapping.

Another object of my invention is to provide a plug for a plug valve wherein the threaded end of the plug may be comparatively larger than has heretofore been provided.

Other objects of my invention will become evident from the following detailed description,

,, taken in conjunction with the accompanying drawings, in which Fig. 1. is a side elevational view of my novel P Y Z' 2 is. a plan view of my novel plug-valve;

Fig. 3 is a side elevational' view of my novel plug valve with the lower part thereof in section for better illustration; and

Fig, is a view taken onthe line 3 throu h the plug,

Referringnow to the drawing; 1 show: in Figs; 1;, 2,31 and 4, a plug valve comprisinga cylindrical body I; having aligned apertures, 2 and 3 extending laterally outwardly thereof in boss/ed portions t and 5 to, provide an inlet and an outlet for the plug Valve. The body I has a vertically extending, internal, tapered seat 6; for seating a, stop plug'L An outwardly extending. apertu edr o king a m 8 s. pr id d on; th upp end of the body I. A skirt 9 depends from; the body I and it provides an open, cylindrical-1y shaped nestin chamber Hi for a spring H- which is disposed around the reduced portion l2 of the plug T. The. inner diameter of the spring H large enough to permit free vertical movement of; the portion of the plug; 1 above the reduced portion I21 The Plug, I has. a. further reduced depending threaded portion l3 with a lo gitudinally ext ndin s mi-c la Shaped groove M, for threadably engaging a threaded member 1.5?With alon itlidinal'ly extending semircular shap d groove. 76 co espo ne h groov 1.4 the threaded, end l3'of-theplug1. Theouter side. 31: o the threaded m mbe I is. tapered sothat it cannot be en ag by 1-12 13: Wrench or. any other type ofwnench- Th semi.- circular. shaped grooves. t4. and; ii pro ide. a cylindrical. aperture. when aligned" for receiving, a p n la. which. lacks the. th eaded member l5; and: the thr aded. nd. I'3 against r lat ve r tation. Th pin. I18 has. a, diameter several thousan ths. a inch greater t an he 'nmete term d by he cylindrical grooves I I and i6 thereby providing a press fit for the pin l8 when it is pressed or driven into the cylindrical portion formed by the grooves l4 and IS. The reduced portions l2 and [3 of the plug 1 form a shoulder [9. The upper end of the plug I has a reduced cylindrical portion 20 with a laterally outwardly extending apertured locking arm 2| corresponding to the locking arm 8 on the body I. A key 22 of the flat type extends upwardly from the plug 1 for rotation thereof. The plug 1 has a centrally disposed, longitudinally extending aperture 23 centrally thereof adapted to align with the inlet and outlet apertures 2 and 3 to permit the flow of fluid through the body I when the plug 1 is in a rotational position as shown in Fig. 3.

4-4 of Eig.

In the assembly of my novel plug valve, it is merely necessary to dispose the plug 1 on the seat 6 of the body I as shown particularly in Fig. 3, place the spring I2 around the reduced portion [2 of the plug 1, and threadably engage the threaded member 15 with the threaded end I3 of the plug 1 until the threaded member l5 engages the shoulder I9 formed between the reduced portion I2 and the threaded end I3 of the plug I. By providing the shoulder IS, the threaded member I5 is locked thereagainst and alignment of the grooves I4 and I6 is simplified. The semi-circular shaped grooves I4 and I6 in the threaded end I3 and threaded member [5 respectively are aligned and the pin I8 is forced therein by a suitable press or driving hammer. The plug 1 may then be rotated by the key 22 to an open position with the aperture 23 in the plug 1 aligned with the inlet and outlet apertures 2 and 3 or in a closed position at right angles to its position as shown in Fig. 3. Furthermore, the apertured locking arms 8 and 2| may be aligned and locked by any suitable well known means.

The spring 1 l is of sufficient strength to maintain the plug 1 on its seat 5 in the body I while still permitting free rotation thereof by means of the key 22 without exerting too great a force.

It will be noted that the spring II is enclosed and protected. It will further be noted that the threadable member I5 cannot be engaged by any form of wrench and it is necessary to remove the pin I8 by drilling if the threaded member I5 is to be removed from the plug 1. It will thus be seen that the average user will not be able to remove the threaded member I5 thereby preventing the breaking off of the threaded end l3 of the plug 1 and the blowing out of the plug 1 to cause fires and explosions as has resulted with the use of prior stop cocks in gas lines. The outer side I! of the threaded member I5 may be arcuate in shape without departing from my invention. The outer side of the threaded memher I5 is in alignment with the outer side of It will be evident that other means. than the pin I8 may be provided forlocking the threaded member I5 on thethreaded end l3 of the cock llwith'out departing from my invention.

Fromthe foregoing, itwill be seen that Ihave v provided a tamper-proof plug valve which prevents removal of the plug, which prevents rotation of. the threaded member connecting the threaded end of the p andilany resultant shearing of the end of the plug and which has 4 spring means and other structural elements which provide an efiicient and durable plug valve with long life and one which requires few replacements and repairs.

Various changes may be made in the specific embodiment of my invention without departing from the spirit thereof or from the scope of the appended claims.

What I claim is:

l. A plug valve comprising a body having a tapered seat and an inlet and an outlet and a depending skirt, a rotatable tapered plug disposed on said seat having an apertured portion for registration with said inlet and said outlet and having a reduced threaded end with a longitudinally extending groove on the peripheral surface thereof, said threaded end defining a shoulder spaced a predetermined distance from the end thereof, an inverted, conical shaped threaded member for threadably engaging the threaded end of said plug and said shoulder and having the lateral outer side thereof tapered and coincidental with a contour line embodying the outer side of said body, a portion of said threaded member being telescopically disposed in said skirt and being relatively movable thereto a predetermined distance, said threaded member having a longitudinally extending, semi-circular shaped internal groove for registration with the groove on the end of said plug, a pin disposed in said registered grooves engaging said threaded end of said plug and said threaded member, and a coil spring surrounding said plug within said skirt and engaging said threaded member for urging said plug on its seat.

2. A plug valve as set forth in claim 1 wherein the end of said tapered threaded member has a shoulder normal to the axisof said tapered threaded member and spaced a predetermined distance from the end of said skirt whereby said threaded member is movable a predetermined distance relative to said skirt longitudinally. JAMES G. BRADBURY.

REFERENCES CITED The following references are of record in the file of this patent: I

o UNITED STATES PATEN'I'S' Number 

